Disbarking machine



Nov. 28, 1933. H. STUVE 1,937,073

DISBARKING MACHINE Filed Dec. 11, 1951 Hem/1M Szre Patented Nov. 28, 1933 UNITED STATES DISBABKING MACHINE Heinrich Stiive, Mecklcnburg, Germany Application December 11, 1931, Serial No.

580,405, and in Germany August 18, 1930 9 Claims. (01. M L-208) This invention relates to a novel portable machine for disbarking or peeling timber and comprises as an essential element a traveling chain equipped with disbarking tools which may be ap-.

6 plied to felled trunk timber by means of a movable lever mechanism. My invention further comprises certain modifications of the arrangement of the aforementioned lever mechanism as will be more fully described hereinbelow and pointed out 10 in the appended claims.

On account of the fact that disbarking of the trunks constitutes a considerable item of the total costs, especially in case of wood used for the mining and the paper industry, there is in general a great demand for a practical disbarking machine permitting to perform the operation of disbarking trunks of timber at reasonable cost. There are known hand machines for disbarking trimks of timber, said machines operating with rotating tools of the form of milling cutters. However, machines of this kind have so far found application only to a rather limited extent. I have found that in connection with portable disbarking machines especial advantages may be attained by as mounting the disbarking tools on a chain, traveling across the trunk on guide means riding on the trunk and disbarking it all over its length when the machine is manually shifted along the trunk. My invention provides a disbarking machine which is easily portable and permits the use of the aforementioned advantages offered by the use of a chain in stationary machines also for the disbarking of felled timber lying on the ground in forests. In contra-distinction to known machines of this kind, the chain of my present ma- :hine is only of a very small width and the machine is shifted along the trunk of timber when removing the bark therefrom. Especially good peeling properties may be attained with my present machine if a chain is used which is provided on its side towards the trunk of timber with smooth sliding surfaces and equipped with peeling knives only at its front edge. A chain constructed in this manner may be carried around a trunk of timher to slide round the trunk at great velocity, for instance, of an eifectiveness equal to that used in connection with band-saws. The bark may be removed with my present machine from the trunk of timber by shifting or feeding the machine forward along the trunk during the operation of disbarking, without injuring the surface of the wood by the peeling tools. A machine constructed according to my invention will produce an amount of work equal to from ten to twenty times that heretofore attainable by hand.

In the accompanying drawing I have shown an example of a construction of my present machine as well as some details of the construction of the chain and the peeling tools carried thereby. Fig. 1 is a side view of my new machine during its application to the trunk of timber, with some parts in section, Fig. 2 an enlarged diagrammatic longitudinal section through the trunk with the chain and disbarking tools partly in cross-section, Fig. 3 a top-view of the chain and the disbarking tools shown in Fig. 2, Fig. 4 a cross-section through the trunk with the chain and disbarking tools in end view and Fig. 5 a section similar to Fig. 2 showing a modified construction of the disbarking tools.

According to Figs. 1 to 3 the general construe-.- tion and mode of operation of my present machine is as follows: Mounted upon the shaft of the motor 1 is a sprocket wheel e which serves for imparting motion to the chain t with the peeling tools 12 thereon. Further guide or sprocket wheels h, m and o serve for guiding the chain it around the trunk a. Only a small portion of the chain along the trunk is shown in Fig. 1, while the greater part of said chain is merely indicated by a dash-and-dot line for the sake of clearness. In Fig. 1 it is assumed that motion of the chain takes place from left to right over the bark of the trunk of timber. The lever mechanism for operating the machine and for adjusting the chain t comprises a lever b permitting to operate a further lever 0 having the form of a telescope arm with the tension roller 0- thereon, a transmission gear 11 intermediate said lever b and said lever c, said levers thus positively adjusting the length of the portion of the chain intermediate the guide or sprocket wheels m and h to span the trunk of timber independently of its diameter about the same portion of its circumference, whenever the lever 17 and the arm a are pressed against the trunk. Preferably the amount of span of the chain is so chosen that about one half of the circumference of the trunk is worked by the chain, as in this case, and it will be possible to fully disbark the trunk in two working steps. If there is no trunk intermediate 100 the lever b and the arm a, the former is'swung into inoperative position, that is towards the arm a by action of the spring g, the tension lever 0 having its largest deflection in this "condition of the machine. By action of the spring 'p within the telescoping tension lever c provision is made to always keep the chain t in tensioned condition. The spring p is preferably so dimensioned that during operation of the machine, that is during disbarking a trunk of timber, said spring will not be quite in its end position but have a certain play. -This play allows the tension roller 0 to accommodate itself to any stress on the chain t by uneveness of the trunk, which may occur on the way of the machine. The rollers l and k serve for shifting or feeding forward the machine along the full length of the trunk, said rollers l and k being preferably driven from the shafts of the guide or sprocket wheels m and h, preferably by means of worm gears as indicated at i and n in Fig. 1. The disbarking machine as a whole is kept in position by an attendant which walks along the trunk of timber during operation of the machine.

As Fig. 2 clearly shows the chain t moves upon slide surfaces w and w around the trunk z. The cutting edges 12 of the knives are positioned laterally of the chain and bent in upward direction.

In this manner the slide surfaces will carry the knives around the trunk at a proper distance from the interior core of wood.

The construction shown in Fig. 2 shows that the cutting edges of the knives v at the upper end of the trunk will always be carried therearound at a proper distance therefrom. In order to avoid, in case of an irregular surface of the trunk, injury to the interior core of wood by said knives, the cutting edges are made to extend not entirely down to the plane of the slide surfaces 10 and w on the chain. A part of the bast hide g which is only of small'thickness, as compared with the bark a: proper, will be kept out of contact with the edges of the knives v and removed with certainty by said surfaces w and in, which slide on the wet bast hide and take it oif by friction. By subdividing the slide surface of the chain into two parts w and w which are sepa-- rated from each other by an interstice the chain will be securely guided and always assume a stable position, even in case of an irregular surface of the trunk; as a result of this there will be attained proper and full separation of the bark at: including the bast hide y independently of the thickness of the bark and without any loss of wood.

In order to apply the machine to a trunk of timber, the distance between the two rollers h and m is enlarged by swinging the movable lever 11 outward to such an extent that the machine may now be set upon the trunk with the lever b and the arm a straddling the trunk. In this position the machine is ready for the operation of disbarking the trunk a. With the aid of the aforementioned two guide levers or handles there may also be exerted a pressure upon the feed rollers k and Z and this pressure may be regulated during operation of the machine.

v If the roller-s k and l are made of conical form, the feeding motion imparted to the machine may be varied independently of the velocity of the chainby shifting the points of contact between said rollers and the trunk in axial direction of said rollers. By properly arranging the transmission gear d the result may be attained that thepoints of contact between the trunk and the rollers-maybe displaced in such manner that the middle portion of the roller surface is always in contactf'with the trunk, independently of the diameter of the trunk. An arrangement of this kind will considerably enhance the value of the machine, especially since the friction'is rather small in spite of the large velocity of motion of the chain which is due to the fact that the surfaces at which friction may arise bet e n the chain and the trunk are smooth and that cutting edges are only present at the front edge of the chain.

The chain which constitutes the carrier for the peeling knives may be of various forms of construction as shown, for instance, in Figs. 2, 3, 4 and 5.

According to Figs. 2, 3 and 4 cutting edges 0 are provided at the side t of the chain, said cutting edges 12 being integral with the slide members w and 10 as shown especially in Fig. 3.

A roller chain is preferable in view of the large velocity attainable therewith. Since roller chains have only very thin chain links ofiering rather small slide surfaces, it will be preferable to use a roller chain having its links equipped with special extensions forming the slide surfaces. In order to keep these slide surfaces at one of their edges as much as possible in a position parallel to the trunk, it is preferable to give said slide surfaces a width essentially greater than the width of the chain.

In case of roller chains the chain links may also be made of such strength that the contact with the trunk will be sufliciently large to act as a slide surface; in this case the knives or cutting edges may be bent out of the chain links as indicated in Fig. 5.

After having disbarked the upper half of the trunk of timber, the latter is rotated through an angle of 180 so that now also the bark may be removed from the other half of the trunk. The thin end of the trunk is preferably placed upon a jack which is equipped with a ripp g or fastening device to keep the trunk in position.

By my present invention I have solved the problem of devising a peeling tool in the form of a chain in connection with an easily movable and portable disbarking machine which may be operated by hand. By the use of the aforedescribed novel construction of chain in a portable disbarking machine the operation of disbarking will be greatly improved as compared with known machinery in qualitative as well as in quantitative respect.

I claim:

1. A machine for debarking trlmks comprising a frame mounted for movement longitudinally of the trunk, said frame including arms designed to slidably grip the trunk, and a debarking element carried by the frame and arms and operating transversely between the arms, said debarking element including cutting elements operating above the trunk-engaging portion of the element.

2. A machine for debarking trunks comprising a frame mounted for movement longitudinally of the trunk, said frame including arms designed to slidably grip the trunk, and a debarking element carried by the frame and arms and operating transversely between the arms, said debarking element including relatively fiat trunk-bearing surfaces with outstanding, upturned cutting elements.

3. A debarking machine including a frame, arms carried thereby for opposed bearing on a tree trunk, one of the arms being movable with respect to the frame, an endless debarking element carried by the frame and arms and having a portion intermediate the arms for cooperation with the bark on the trunk, and means automatically controlled by the relative spacing of the arms for tensioning said element.

4. A debarking machine including a frame, an arm rigid therewith, an arm movably mounted therein, means at the free terminals of the arms for engaging a tree trunk on opposite sides thereof, a flexible debarking element movable in the frame and arms and. cooperating with the bark on the tree intermediate the arms, means carried by the frame for operating the element, and means carried by the arms for moving the frame longitudinally of the tree trunk, said means being operated in the movement of the debarking element.

5. A flexible debarking element for debarking machines including a chain-like member'having relatively flat bearing portions to engage a tree trunk, and cutters carried by said bearing portions and upturned relative thereto for cutting the bark.

6. A debarking machine including a frame, arms carried thereby, one of the arms being movable with respect to the frame, an endless chain movable in the frame and in the arms and presenting an operative area between the free ends of the arms, debarking cutters carried by the chain, a tensioning arm carried by the frame over which the chain passes, and means for operating the tensioning arm in the movement of the movable arm to maintain the chain tensioned regardless of the spacing between the arms.

7. A debarking machine including a frame, arms carried thereby, one of the arms being movable with respect to the frame, an endless chain movable in the frame and in the arms and presenting an operative area between the free ends of the arms, debarking cutters carried by the chain, a tensioning arm carried by the frame over which the chain passes, means for operating the tensioning arm in the movement of the movable arm to maintain the chain tensioned regardless of the spacing between the arms, rollers carried by the arms to engage a tree trunk, and means for operating the rollers for feeding the frame longitudinally of the tree trunk in the movement of the chain.

8. A debarking machine according to claim 5, wherein the debarking cutters are integral with the chain-like member. I

9. A debarking machine according to claim 6, wherein the tensioning arm is formed of a partially hollow sleeve having a second partially hollow sleeve slidable therein and forced apart by a compression spring carried to said sleeves.

HEINRICH s'rtivn. 

